Messaging protocol

Server structure

Core processes ran as gen_server

• mc_erl_chunk_manager
• mc_erl_entity_tracker
• mc_erl_tcp_listener
• mc_erl_event_passer
• mc_erl_player_sup

Data formats

• chunk_location -> {X, Z}
• block_location -> {X, Y, Z}
• entity_position -> {X, Y, Z, Yaw, Pitch}
• chunk_column_data -> {chunk_column_data, Full_column, Types=[{SubchunkID, Binary}, {SubchunkID, Binary}, ...], Metadata=[{SubchunkID, Binary}, {SubchunkID, Binary}, ...], Block_light=[{SubchunkID, Binary}, {SubchunkID, Binary}, ...], Sky_light[{SubchunkID, Binary}, {SubchunkID, Binary}, ...], Add_data=[], Biome=Binary}
• block_data -> {Type, Metadata, Block_light, Sky_light, Biome}

Message formats

mc_erl_chunk_manager

• Call {get_chunk, Chunk_location} - looks chunk up in storage or generates it. Returns #chunk_column_data.
• Call {get_compressed_chunk, Chunk_location} - fetches a chunk in a get_chunk-like action, encodes it, stashes result in its private cache and returns raw binary chunk data.
• Cast {set_block, Block_location, Block_data} - sets a block in the world.

mc_erl_entity_tracker

• Call {register_entity, Type, Supervisor} - Type is player, mob or drop. Registers entity with entity_location_update message destination Supervisor and returns Eid. Supervisor may be none.
• Call '{register_entity, Type, Supervisor, Entity_position}` - same as above, but also initializes it with starting position.
• Cast {update_entity, Eid, Entity_position} - Updates entity position and broadcasts this to each Supervisor of entities nearby.
• Message format for entity_tracker's casts to supervisors: {entity_location_update, Eid, NewLocation}